Compositions for combating nematodes



COMPOSITIONS FOR COMBATING NEMATODES Ewald Urbschat, Koln-Mulheim, and'Bernhard Homeyer,

Koln-Stammheim, Germany, assignors to Farbenfabriken BayerAktiengesellschaft, Leverkusen, Germany, a corporation. of Germany I No Drawing. Application December 5, 1956 Serial No. 626,307

Claims priority, application Germany December 9,1955

Claims. Cl. 167-30) The present invention relates to a method forthe combating of nematodes as well as to nematocidal compositions containing as active ingredients compounds of the following formula in which R standsfor an amino or hydroxygroup which may furthermore be substituted by aliphatic or aromatic radicals or for the radical of aliphatic or aromatic hydrocarbons, X may be O, S or NH (instead of C=X also the S0 group may be convenient) R may be azo and hydrazo radicals, R stands for a phenyl substituent such as alkyl, alkoxy, halogen or nitro and R and R each being hydrogen or R +R being oxygen.

Nematodes infecting the soil have previously been combated by a number of processes which, however, suffer from various disadvantages. To omit for some years cultivating plants which are especially predisposed to attacks by nematodes is unsatisfactorily. Disinfection of the soil by treatment with gaseous nematocides is costly and, however, restricted to relatively small areas of soil. The efliciency of chemical compositions heretofore proposed for combating nematodes by incorporating them into the soil is also often limited. Besides, most of the hitherto known chemical compositions cause damage to plants and are difiicult and hazardous to handle.

In accordance with the present invention it has now been found that certain derivates of quinone oxime semicarbazone which correspond to the following formula can be used with advantage to combat nematodes. The foresaid compounds which are known in principle and which can be prepared in simple manner by known methods is distinguished by an outstanding effect in killing nematodes. Besides, these compounds of the invention are odorless, show a low volatility and low toxicity to plants and mammals.

It has further been found that particularly the reduction and oxidation products of the quinone oxime semicarbazone, namely the amino phenyl carbamic acid hydrazone of the formula (or its derivatives substituted as mentioned above such as the corresponding thiocarbonic acid hydrazone or guanyl-hydrazone as well as such compounds which bear in the phenyl radical lower alkyl substituents such as the methyl or ethylgroup or halogen such as chlorine or bro- 2,922,741 Patented Jan. 26, 1960 mine or a nitrogroup), the amino carbonic acid-azo-p aminobenzene of the formula 1 (or its derivatives substituted as mentioned above such as the corresponding thiocarbonic acid hydrazone or guanylhydrazone as well as such compounds which bear in the phenyl radical lower alkyl substituents such as the methylor ethylgroup or halogen such as chlorine or bromine or a nitrogroup), and the amino carbonic acid-azo-pnitrosobenzene of the following formula (or its derivatives substituted as mentioned in the first formula such as the corresponding thiocarbonic acid hydrazone or guanyl-hydrazone aswell as such compounds which bear in the phenyl radical lower alkyl substituents such as the methylor ethylgroup or halogen such as tion of 30 minutes the amino carbonic acid-azo-p-nitrosobenzene is filtered with suction and recrystallised from dimethylformamid/methanol. It melts at C(under decomposition.

Besides the functional derivatives and "substitution products of all these compounds may efficiently be used for combating nematodes. Probably the molecular configuration is responsible for the nematocidal properties, since substances wherein the NH -group is replaced by organic radicals, which may be linked to the 0:0 group directly or via hetero atoms, show likewise nematocidal activity.

The CO-group also may be replaced by a CS-,

C=NH-- or SO -group.

The carbamic acid derivatives, which are especially effective nematocides, are incorporated into the soil either as such or in form of their salts preferably after admixing them with inert liquid or solid carriers. Nematodes such as Heterodora schachtii Meloidogyne spec. and the like may elfectively be killed. Suitable inert liquid carriers are for instance water (if necessary withcommercial emulsifiers), lower aliphatic alcohols such as methanol,

ethanol, isopropanol, etc., while chalk, talcum, bentonite,

and clay shall be mentioned as examples of solid as Examples Themematocidal activity of the compounds of the invention was determined by applying them to nematodes of the group meloidogyne spec.

(1), Laboratory tests-The active ingredients 'were' dissolved in water at the concentrations indicated in the following table, and the aqueous compositions obtained were applied to the abovesaid nematodes for 24 hours. The table shows thenumber of nematodes 'killed after that time in percentage.

Killing effect Amiuophen- Aminocar- Amiuoear Gone. ylcarbamicbonic acidbonic acidaeidazo-p-aminoazo-p-nitrohydrazone benzene so benzene Percent Percent Percent Percent 0. 1 100 100 100 0.01 100 100 100 0.005 80 90 100 0.001 20 50 80 (2) Greenhouse test.The activesubstauces were incorporatedinto the infectedsoil in the form of dust or spray compositions containing 10% of active ingredient ingredientan effective ="amount of a compound-"oi formula in which R stands for an aminogroup, X stands for a member selected fromthe group consistingof oxygem sulfur. and an. iminogroup, -R standsfor a member- 'selectedfr'om the group consisting of'azo and hydrazo radicals, R stands "for a member 'selectedfrom the group consisting of hydrogen, lower-alkyl, .chloro," bromo:and nitrogroups and R R stands for a member selected. from the group consistingof two hydrogen"atoms"andone oxygen atom and an inert pesticidal rier therefor.

adjuvant as a car- 3. A nematocidal composition containing as an active ingredient an efiec'tive amount of'a compound of the 4 formula in which R stands for an aminogroup, ,Xstands for a member selected from the. group consisting of oxygen,

sulfur and an iminogroup, R stands for a member selected from the group consisting of azo and hydrazo radicals, R stands for a member selected from the group: consisting of hydrogen, lower alkyl, chloro, bromo andnitrogroups and R R stands for a member selected from the group consisting of two hydrogen atoms and one:

oxygen atom and a commercial fertilizer.

4. A process for combating nematodes which comprises 5 applying to soil infected with nematodes an effective:

amount of aminophenylcarb'amicacidhydrazone.

5. A process for combating nematodes which. comprises applying to soil infected with nematodes an effective? amount of aminocarbonicacid-azo-p-aminobenzene;

6. A process for combating nematodes which comprises: applying to 'soil'infected with nematodes an eifective' amount of aminocarbonicacid-azo-p-nitrosobenzene.'

References Cited-in thefile of this patent 1. A method of combating nematodes which comprises applying to soil infected iwith nematodes an eifective amount of a compoundof the'followingformula in-which R stands for an aminogroup, X stands for a member selected from the group consisting ofoxyg'en, '55 suIfurvandzan iminogroup, R stands for a member selected from::thegroup consisting ofazo and-hydraz'o radicals, R stands for a member selected from the group consisting of hydrogen, lower alkyl, chloro, bromo and nitrogroups anduR R stands for a member selected from the-group consisting of two hydrogen atoms and one oxygen L atom..

2,.Anematocidal composition containing as-an active UNITED STATES PATENTS Flint .Dec." 4, 1934 Meisenburg Oct. 13,1936 Gertler Nov. 4, 1941' Tisdale Nov. 30, 1943 Davidson Feb. 3, 1948 Kagy Aug. 31, 1948 Bickerton e June 21, 1949 Carter Mar. 28, 1950 Kay Feb. 27, 1951 Wolf Jan. 29, 1957 FOREIGN PATENTS Australia June 12, 1947- OTHER REFERENCES Frear: Chem. of the Insect., Fung. and Herb. (2nd ed), September 1948, pp. 64, 286-287, 108-122.

Chem. Abs; 1939, -vol. 33, p. 3771(3); 

1. A METHOD OF COMBATING NEMATODES WHICH COMPRISES APPLYING TO SOIL INFECTED WITH NEMATODES AN EFFECTIVE AMOUNT OF A COMPOUND OF THE FOLLOWING FORMULA 